The invention relates to an air cleaner, and particularly, to a dust collector for an air cleaner whose ionizing wire acts as a electric heating wire to heat room as well as to clean air.
In general, an air cleaner comprises a plurality of string or wire type electrodes, a plurality of flat surface electrodes and a high voltage DC power source for supplying high voltage to said both electrodes in order to use the corona discharge between two electrodes having a high voltage difference from each other, so that the unequal electric field is formed between wire electrodes and flat surface electrodes, respectively. That is, as the high voltage is applied to both electrodes having geometrical structure of the line to the surface to generate the corona discharge, the air containing dust particles is passed through the air ion flowing to make the dust into a electric charge based on the fact that the ions are impinged against the solid dust particles and are attached thereto, and the dusts in air are collided with ions by the thermal movement (Brownian movement). Such charged dust particles in the air are collected at the collecting portion of an air cleaner.
A conventional dust collector equipped in an air cleaner is schematically shown in FIG. 4. As shown in FIG. 3, a plurality of dust collecting electrodes 1 made of a conductive metal such as aluminum are arranged at a predetermined gap, for example 10 mm, to each other. A plurality of ionizing wires 2 are disposed at the middle position between two dust collecting electrodes 1, respectively. Ionizing wires 2 are connected to the positive (+) of a high voltage source, for example 7 KV, and dust collecting electrodes 1 are connected to the negative (-), so that the dust particles in the air are made into a positive electric charge by the positive corona discharge. Therefore, when high voltage is applied to the both of electrodes, the positive charged dust particles are collected at the negative dust collecting electrodes by an electric field formed respectively between ionizing wires 2 and dust collecting electrodes 1.
On the other hand, an industrial dust collecting apparatus of one step type generally uses negative corona discharge to make the dust particles into a negative electric charge in order to increase the current density. It has the possibility for recollecting the dust particles scattered again from dust collecting electrodes because a plurality of dust collecting electrodes are arranged along the air flow. Also, a dust collecting apparatus of two step type used mainly in an air cleaner forms the electric fields of the electrifying portion and the dust collecting portion by the separate power sources. Then, the corona discharge normally generates somewhat noxious gases such as Ozone O.sub.3, NO.sub.2 etc. Therefore, an air cleaner is adapted to use the positive corona discharge for making the dust particles into the electric field, in which the positive corona discharge generates a relatively smaller amount of the corona discharge and Ozone comparing with the negative corona discharge.
But, even though a dust collecting apparatus uses the positive corona discharge to produce a relatively small amount of the corona discharge and noxious gases, it must be equipped with at least one active carbon filters for decomposing the ozone at the air inlet and/or outlet ports, and a dust collecting electrodes may be treated with ozone decomposition accelerating silver plating layers. Herein, it is known that if a home air cleaner uses the negative corona discharge with such harmful gases as the ozone or the nitrogen dioxide being removed, an dust collecting apparatus can be installed in a home air cleaner independent upon the use of the negative corona discharge as well as can use the positive corona discharge.
Also, the user may feel the need for a the separate room heating in using an air cleaner, especially in the winter, but any technical contents related with the room heating in a conventional air cleaner has not been disclosed.
Also, considering that an air cleaner is always used in the indoor, it could not have avoided the contamination of the dust or the microbe due to the convection in the enclosed space when used for a long period. It has been requested to clean the inner portion of an air cleaner for removing of the accumulated dust and the bacteria with the contamination removing device.
An example of an air cleaner having the ozone decomposing function is disclosed in U.S. Pat. No. 4,516,991. This cleaning apparatus which comprises a plurality of dust collecting panel electrodes and corresponding panel electrodes arranged, respectively opposite to each other at a predetermined interval to form air flow passages in a casing having an air flow inlet and an outlet, and a number of ionizing wires installed at a predetermined distance from the ends of the dust collecting panel electrodes substantially on extension lines extended from the respective corresponding electrodes outwardly from the intervals. Furthermore, the dust collecting panel electrodes, the corresponding panel electrodes, and the ionizing wires may be provided at narrow intervals so that the corresponding panel electrodes and the ionizing wires is equal polarity to that of the dust collecting panel electrodes. The voltage applied between the dust collecting panel electrodes and the corresponding panel electrodes is set to substantially one-second of that applied between the dust collecting panel electrodes and the ionizing wires, and the length of the intervals between the dust collecting panel electrodes and the corresponding panel electrodes is of a predetermined potential gradient in response to the applied voltage value. In addition, ozone decomposing accelerating noble metal plating layer is coated on each of the dust collecting panel electrodes and the corresponding panel electrodes, and an ozone decomposing filter formed of activated coal being arranged at the air flow outlet. This air cleaning apparatus of the invention can thus improve the dust collecting efficiency in a sufficient degree in practical use and can reduce the ozone flow rate.
But this patent doesn't disclose the technical contents that an air cleaner heats room when the indoor temperature is below a predetermined temperature.
Accordingly, the object of the invention is to provide a dust collector for an air cleaner for heating of a room if the indoor temperature is a relatively lower.
The other object of the invention is to provide a dust collector for an air cleaner for sterilizing of the bacteria harmful to human body, if necessary, as well as for heating of a room by heating an air to be cleaned.
Therefore, according to the invention, an air cleaner comprises a dust collector of the negative corona using high voltage, in which a plurality of dust collecting panels are connected to a high voltage source, for example DC 7 KV to collect the dust particles in air, a plurality of ionizing wires function as the heating wire, and the separate voltage source heats said ionizing wires. Also, the voltage source for the ionizing wire is a relatively lower voltage source, for example DC 24 V, DC 48 V which may be overrided comparing with the voltage difference between the electrifying panel and the ionizing wire so as to prevent the ill influence on the electrifying function and the dust collecting function.
Therefore, a plurality of electrifying panels are connected at their one ends to the plus terminal of a high voltage source. A plurality of ionizing wires are electrically coupled at their one ends to the plus terminal of a low voltage source and at their other ends to the minus terminal of a low voltage source, in which the minus terminal is the common terminal of a high voltage source and a low voltage source. Therefore the ionizing wire may be heated by a low voltage source connected to its both ends to act as the heating wire, so that it increases the air temperature contacting with the air to be cleaned as well as burns the bacteria to perform the sterilization function. While it is influenced ill on the electrifying function and the ionizing function, since the voltage on one end of the ionizing wire may be disregarded in comparison with the voltage of the electrifying panel.
Also, an air cleaner of the invention generates a relatively larger amount of noxious gas harmful to human body since it uses the negative corona on the contrary to an air cleaner of the positive corona type, but it can prevent the leakage of the noxious gases therefrom using the ozone decomposing active coal. As a result, it may not reduce advantage on the invention.